Problem: The sum of $6$ consecutive integers is $321$. What is the sixth number in this sequence?
Call the first number in the sequence $x$ The next integer in the sequence is $x + 1$ The sum of the $6$ consecutive integers is: $x+ (x + 1)+ (x + 2)+ (x + 3)+ (x + 4)+ (x + 5) = 321$ $6x + 15= 321$ $6x = 306$ $x = 51$ Since $x$ is the first number, $x + 5$ is the sixth integer. Thus, the sixth number in the sequence is $56$.